right angle



the angle formed by two radii of a circle that are drawn to the extremities of an arc equal to one quarter of the circle; the angle formed by two perpendicular lines that intersect; an angle of 90°.

Origin of right angle

Middle English word dating back to 1350–1400
Related formsright-an·gled, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for right angle

Contemporary Examples of right angle

  • The only one present who was seated like a man, legs crossed at right-angle, was Whoopi Goldberg.

    The Daily Beast logo
    Obama's Televised Turn-Off

    Tunku Varadarajan

    July 29, 2010

  • In 1933, Ben Shahn loaned Walker Evans a right-angle viewfinder, which he took on assignment to Vicksburg, Mississippi.

    The Daily Beast logo
    Furtive Photography

    Philip Gefter

    May 27, 2010

Historical Examples of right angle

  • Obtuse, an angle having a wider opening than a right-angle or "perpendicular."

  • At the epicentre, the angle of emergence is a right-angle; at a great distance from the epicentre, it is nearly zero.

  • Its bole, five feet of stalwart diameter, rose straight and tapering to the first right-angle limbs, each in itself almost a tree.

    The Roof Tree

    Charles Neville Buck

  • At length he rose and climbed on, presently turning at a right-angle to bisect the strip to its boundary before he paused to rest.

    The Valiants of Virginia

    Hallie Erminie Rives

  • The toe is never pointed in line with the leg, but held at a right-angle to it, as in the standing position.

    The Morris Book

    Cecil J. Sharp

British Dictionary definitions for right angle

right angle


the angle between two radii of a circle that cut off on the circumference an arc equal in length to one quarter of the circumference; an angle of 90° or π/2 radians
at right angles perpendicular or perpendicularly
Related formsRelated adjective: orthogonal
Derived Formsright-angled, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

right angle in Science

right angle


An angle having a measure of 90°.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

right angle in Culture

right angle

An angle measuring ninety degrees, formed by the intersection of two perpendicular lines. (Compare acute angle and obtuse angle.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.